Wildcards :num and :any not working in my routes

[eluser]Unknown[/eluser]
I'm having a problem with wildcards in routes. The routing works, if I don't use wildcards or regular expressions.

Code:

$route['item/:num'] = "item/index";

Doesn't work (results in CI 404), while

Code:

$route['item/test'] = "item/index";

does work.

I thought maybe it is because of conflicting .htaccess rules, but with a disabled .htaccess it still doesn't work. Any ideas?